ErrLookup › GoogleChrome/lighthouse
GoogleChrome/lighthouse
Automated auditing, performance metrics, and best practices for the web. · JavaScript · 510 source files
Analyzed at 9515cd4e58 on 2026-08-13. 137 documented errors.
| Code / Message | Type | Severity | Tags |
|---|---|---|---|
INVALID_SPEEDLINE Chrome didn't collect any screenshots during the page load. Please make sure… | exception | error | runtime, chrome, performance, trace, speedline, headless |
| Unknown directive | validation | warning | seo, robots-txt, validation |
NO_SCREENSHOTS Chrome didn't collect any screenshots during the page load. Please make sure… | exception | error | runtime, chrome, screenshots, trace, headless |
| Please provide a url | validation | error | cli, validation, usage |
| Launching Chrome on Mac Silicon (arm64) from an x64 Node… | exception | error | platform, macos, arm64, environment, chrome |
| Invalid precomputed lantern data file | validation | error | cli, config, lantern, json, performance |
| No lantern metrics available, did you run… | validation | error | lantern, data-pipeline, baseline, ordering |
NO_TTI_NETWORK_IDLE_PERIOD Your page took too long to load. Please follow the opportunities in the report… | exception | error | tti, network, performance, metrics |
NO_LCP_ALL_FRAMES The page did not display content that qualifies as a Largest Contentful Paint… | exception | error | lcp, trace, performance, metrics, all-frames |
| Unrecognized screenEmulation option | validation | error | cli, validation, emulation, unreachable, internal |
UNSUPPORTED_OLD_CHROME This version of Chrome is too old to support | exception | error | responsiveness, inp, chrome-version, compatibility, trace |
NO_TTI_CPU_IDLE_PERIOD Your page took too long to load. Please follow the opportunities in the report… | exception | error | tti, cpu, performance, metrics, javascript |
| CSV output is not support for user flows | exception | error | csv, user-flows, report-generator, output-mode |
| No metrics for | validation | error | lantern, metrics, evaluation, validation |
| run failed to get metrics | exception | error | lantern, metrics, lighthouse-result, data-collection |
NO_DCL Something went wrong with recording the trace over your page load. Please run… | exception | error | tti, trace, navigation, performance, metrics |
| unsupported JSDoc comment | validation | error | i18n, jsdoc, typescript-compat, collect-strings |
SPEEDINDEX_OF_ZERO Chrome didn't collect any screenshots during the page load. Please make sure… | exception | error | speedline, speed-index, trace, performance, metrics |
NO_LCP The page did not display content that qualifies as a Largest Contentful Paint… | exception | error | lcp, trace, performance, metrics, breakdown |
| Unsupported gather mode | exception | error | user-flow, gather-mode, internal-invariant |
| Gatherer for did not support any gather modes. | exception | error | config, lighthouse, gatherer, validation, gather-mode |
| Gatherer for did not define a "getArtifact" method. | exception | error | config, lighthouse, gatherer, validation, artifact |
| Invalid sitemap URL protocol | validation | warning | seo, robots-txt, validation, url, protocol |
| `getStandaloneReportHTML` is not set | exception | error | report-ui-features, configuration, options, renderer |
| could not fetch data for locale | exception | error | localization, locale, viewer, network, i18n |
| has an invalid category description. | validation | error | config, lighthouse, plugin, validation, i18n |
| supportedModes must be an array, valid array values are… | validation | error | config, lighthouse, plugin, validation, gather-mode |
| Invalid sitemap URL | validation | warning | seo, robots-txt, validation, url |
| Invalid values. Argument 'output' must be an array from… | validation | error | cli, validation, output |
| No user-agent specified | validation | warning | robots-txt, seo, validation, parsing |
| Invalid value: Argument 'extra-headers' must be a string | validation | error | cli, validation, network, headers |
| Invalid value: Argument must be a string or a boolean | validation | error | cli, validation, yargs |
| Invalid value: Argument 'screenEmulation' must be an… | validation | error | cli, validation, emulation |
| Step " " did not return a result | exception | error | user-flow, audit, runner, internal-error |
| Error | exception | error | github-api, gist, network, rate-limit |
| must use same format and formatType for a given name… | validation | error | i18n, icu, placeholder, format, collect-strings |
| runtime error | exception | error | lighthouse, runtime-error, wpt, lantern, retriable |
| Responsiveness currently unsupported by simulated throttling | exception | error | responsiveness, inp, throttling, not-implemented, metrics |
| Gatherer for did not provide a meta object. | exception | error | config, lighthouse, gatherer, validation, artifact |
| provided json is not a Lighthouse result | exception | error | treemap, validation, lhr, json |
NO_SPEEDLINE_FRAMES Chrome didn't collect any screenshots during the page load. Please make sure… | exception | error | speedline, screenshots, trace, performance, metrics |
| has no audit() method. | exception | error | config, lighthouse, audit, validation |
| plugin name ' ' does not start with 'lighthouse-plugin | validation | error | config, lighthouse, plugin, validation, naming |
| Timespan already in progress | exception | error | user-flow, state-machine, timespan, navigation |
| Unsupported locale | exception | error | localization, locale, i18n, format |
| FCP All Frames not implemented in lantern | exception | error | fcp, lantern, throttling, metrics, not-implemented |
| JSON file was not generated by Lighthouse | exception | error | viewer, validation, lhr, json |
| Pattern should either be empty, start with "/" or "*" | validation | warning | robots-txt, seo, validation, parsing |
| fetching gist | exception | error | github-api, gist, network, rate-limit, http-status |
| Navigation already in progress | exception | error | user-flow, state-machine, navigation |
| plugin name ' ' not allowed because it is the id of a… | validation | error | config, lighthouse, plugin, validation, categories |
| Invalid value: Argument 'throttling' must be an object… | validation | error | cli, validation, throttling, performance |
| Invalid value: 'throttling. | validation | error | cli, validation, throttling, performance |
| UIStrings defined in file but not exported | validation | error | i18n, uistrings, export, collect-strings |
| Need at least one step before getting the result | exception | error | user-flow, result-generation, validation |
| LCP All Frames not implemented in lantern | exception | error | lcp, lantern, throttling, metrics, not-implemented |
| "$" should only be used at the end of the pattern | validation | warning | robots-txt, seo, validation, parsing |
| Failed to find a Lighthouse report | exception | error | github-api, gist, validation, file-format |
| Invalid value: Argument 'locale' must be a string | validation | error | cli, validation, i18n |
| has no meta.id property, or the property is not a string. | exception | error | config, lighthouse, audit, validation |
| no script treemap data found | exception | error | treemap, audit, open-tab, validation |
| has an invalid group title. | validation | error | config, lighthouse, plugin, validation, groups, i18n |
| expected locale file to exist | validation | error | i18n, locale, trace-engine, dependency, filesystem |
| Incorrectly formatted @example | validation | error | i18n, jsdoc, example-tag, collect-strings, validation |
| Ctc messages cannot contain double dollar | validation | error | i18n, ctc, placeholder, collect-strings, internal-format |
| has an invalid category manualDescription. | validation | error | config, lighthouse, plugin, validation, i18n |
| groups json is not defined as an object. | validation | error | config, lighthouse, plugin, validation, groups |
| unrecognized category in 'onlyCategories | validation | error | config, lighthouse, filters, validation, categories |
| string collision: `message` and `description` are the same… | validation | error | i18n, collision, placeholder, deduplication, collect-strings |
| [ ] Did not find the expected syntax in message | validation | error | i18n, icu, syntax-error, collect-strings, message-format |
| UIStrings exported but no definition found | validation | error | i18n, uistrings, export, collect-strings, regex |
| " " is not a valid 'output' value. Argument 'output' must… | validation | error | cli, validation, output |
| is not defined as an object. | validation | error | config, lighthouse, plugin, validation |
| Save already in progress | exception | warning | github-api, gist, concurrency, reentrancy |
| `lighthouse:default` is the only valid extension method. | validation | error | config, lighthouse, validation, extends |
| configPath must be an absolute path | validation | error | config, lighthouse, filesystem, paths |
| Content cannot appear outside plural or select ICU… | validation | error | i18n, icu, plural, select, collect-strings, message-format |
| unexpected response | exception | error | wpt, polling, api, lantern, state-machine |
| Invalid value: 'screenEmulation. | validation | error | cli, validation, emulation |
| Syntax not understood | validation | warning | robots-txt, seo, validation, parsing |
| Usage $0 | validation | error | lantern, baseline, filesystem, cli-usage, assertion |
| onlyAudits cannot be an empty array. | validation | error | config, lighthouse, filters, validation, audits |
| Invalid output mode | exception | error | report-generator, output-mode, validation |
| Could not find with site URL | validation | error | cli, lantern, site-index, url-mismatch |
| Usage $0 | validation | error | cli, usage, lantern, file-not-found, ordering |
| Usage $0 | validation | error | cli, usage, lantern, arguments |
| unexpected status code | exception | error | wpt, api, quota, config, lantern |
| onlyCategories cannot be an empty array. | validation | error | config, lighthouse, filters, validation, categories |
| --output-path ( ) cannot be written to | validation | error | cli, validation, filesystem, output |
| No timespan in progress | exception | error | user-flow, state-machine, timespan, ordering |
| Invalid value: 'screenEmulation. | validation | error | cli, validation, emulation |
| Usage $0 | validation | error | cli, usage, lantern, file-not-found, working-directory |
| has an invalid group description. | validation | error | config, lighthouse, plugin, validation, groups, i18n |
| provided Lighthouse result is missing audit… | exception | error | treemap, audit, validation, lhr |
| missing metric | validation | error | lantern, baseline, metrics, assertion |
| No navigation in progress | exception | error | user-flow, state-machine, navigation, ordering |
| Invalid API response | exception | error | github-api, network, rate-limit, auth, download-issues |
| has a group not defined as an object. | validation | error | config, lighthouse, plugin, validation, groups |
| error fetching | exception | error | network, wpt, fetch, lantern, http |
| Unable to locate ` `. Tried to resolve the module from… | validation | error |